How To Use The Facebook 'Kill Switch' That Hardly Anyone Knows About

There's a setting that acts as a "kill switch" to keep
Facebook apps and other websites from sharing or accessing your
information. It's a useful trick that many people
don't know about, especially if you want as much privacy as
possible while maintaining your account.

It's called "Platform." It's the way third-party games (like Candy
Crush) or websites ("Would you like to sign in using Facebook?")
are integrated with your profile.

It allows not only the apps or sites you visit to access
your data, but the apps and sites your Facebook friends visit as
well.

This is how you turn it off:

First, go to the right hand corner and click "See More
Settings":

Screenshot

Then, select "Apps" from the left hand side:

Screenshot

At the top of the screen, you'll see "Apps you use". If
that feature says "On", you want to turn it off. Click
"Edit":

Screenshot

Now you can turn off "Platform". Remember, this
means you won't be able to log into websites or apps using
Facebook, and friends won't be able to share information with you
through apps.